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    >> It's pretty clear that the IDE drive(r) is *not* waiting for the physical
    >> write to take place before returning control to the user program, whereas
    >> the SCSI drive(r) is.
    >
    >This would not be unexpected.
    >
    >IDE drives generally always do write buffering. I don't even know if you
    >_can_ turn it off. So the drive claims to have written the data as soon as
    >it has made the write buffer.
    >
    >It's definitely not the driver, but the actual drive.

    As I suspected. However, testing shows that many drives, including most
    IBMs, do respond to hdparm -W0 which turns write-caching off (some drives
    don't, including some Seagates). There are also drives in existence that
    have no cache at all (mostly old sub-1G drives) and some with too little
    for this to make a significant difference (the old 1.2G TravelStar in one
    of my PowerBooks is an example).

    So, is there a way to force (the majority of, rather than all) IDE drives
    to wait until it's been truly committed to media? If so, will this be
    integrated into the appropriate parts of the kernel, particularly for
    certain members of the sync() family and FS unmounting?

    --------------------------------------------------------------
    from: Jonathan "Chromatix" Morton
    mail: chromi@cyberspace.org (not for attachments)
    big-mail: chromatix@penguinpowered.com
    uni-mail: j.d.morton@lancaster.ac.uk

    The key to knowledge is not to rely on people to teach you it.

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